Micaela S. Parker

I am a research scientist in the School of Oceanography at the University of Washington. I combine molecular tools and bioinformatics with physiology experiments for the study of marine diatoms. Diatoms are some of the most dominant and important organisms for global carbon cycling in the world’s oceans. They are responsible for about 40% of marine primary production and play a critical role in global climate. Through photosynthesis, diatoms capture the greenhouse gas carbon dioxide and produce oxygen. Annually, diatoms generate one fifth of the oxygen we breathe.

I am specifically interested in the diatom genus Pseudo-nitzschia because many of these species can produce a potent neurotoxin called domoic acid (DA). DA can accumulate in filter feeders such as clams, mussels and oysters. When humans consume shellfish contaminated with DA, they can become very sick. The condition is known as amnesic shellfish poisoning because symptoms include memory loss. DA is also associated with illness and mortality in marine mammals and other vertebrates such as sea birds. I am using comparative transcriptomics (gene expression) to understand the genes that are differentially expressed in Pseudo-nitzschia species when the cells are producing the toxin. The goal is to uncover genes involved in toxin production and develop these as markers for assessing toxin production in field samples. In collaboration with the Joint Genome Institute, we have a draft genome of Pseudo-nitzschia multiseries, in addition to several RNASeq libraries which we are currently analyzing.

I have several other projects that I collaborate on with current and former members in our lab at the Center for Environmental Genomics. These include: the discovery of an iron storage protein called ferritin in Pseudo-nitzschia, which may help explain their success in open ocean iron-poor environments, as well as a metatranscriptome of an iron-addition experiment at Ocean Station Papa (see Adrian Marchetti's website for more information on these projects). Currently, I am also using comparative genomics to investigate strain level diversity within the species Thalassiosira pseudonana (with a lot of help from Chris, Dave and Rhonda in our lab). We have used a SOLiD Analyzer to re-sequence six additional strains (for a total of 7 genomes) and have run light treatment experiments with two of these strains for a whole transcriptome level comparison. I am also collaborating with one of our graduate students, Sara Bender, to investigate the role of the urea cycle in diatoms (see Sara's page for more information). 

 For my Ph.D. thesis research, I investigated the expression of genes involved in the cycling of carbon and nitrogen within a diatom cell during photorespiration. 

 For more information on the Center for Human Health and Ocean Studies, please see our website. For more information on my previous research projects, please see my CV.


  • Ph.D. in Oceanography, University of Washington, 2004.
  • M.S. in Oceanography, University of Washington, 1999.
  • coursework in Plant Pathology, Cornell University, 1994-1995.
  • B.S. summa cum laude in Biology, minor in German, University of Massachusetts, 1994.



  • Port, J.A., M.S. Parker, R.B. Kodner, J.C. Wallace, E.V. Armbrust, E.M. Faustman. (2013). Identification of G protein-coupled receptor signaling pathway proteins in marine diatoms using comparative genomics. BMC Genomics. 14(1):503. doi:10.1186/1471-2164-14-503
  • Read, B.A., et al. (2013). Emiliania’s pan genome drives the phytoplankton’s global distribution. Nature. 499:209–213. doi:10.1038/nature12221
  • Amin, S.A., M.S. Parker, E. V. Armbrust. (2012) Interactions between diatoms and bacteria. Microbiol. Mol. Biol. Rev. 76, 667-684. Journal Cover
  • Marchetti A., D. Schruth, C.A. Durkin, M.S. Parker, R. Kodner, C. T. Berthiaume, R. Morales, Allen, A. E., and E. V. Armbrust. (2012). Comparative metatranscriptomics identifies molecular bases for the physiological responses of phytoplankton to varying iron availability. Proceedings National Academy of Science Plus, USA doi: 10.1073/pnas.1118408109.
  • Bender, S. J., M.S. Parker, E. V. Armbrust. (2011). The coupled effects of light and nitrogen source on the urea cycle and nitrogen metabolism over a diel cycle in the marine diatom Thalassiosira pseudonana. Protist doi:10.1016/j.protis.2011.07.008.
  • Maheswari, U., K. Jabbari, A. E. Allen, J.-P. Cadoret, A. De Martino, M. Heijde, M. Katinka, J. La Roche, P. J. Lopez, V. Martin–Jézéquel, T. Mock, J.-L. Petit, B. M. Porcel, M. S. Parker, A. Vardi, E. V. Armbrust, J. Weissenbach and C. Bowler. (2010). Digital expression profiling of novel diatom transcripts provides insight into their biological functions. Genome Biology 11:doi:10.1186/gb-2010-11-8-r85.
  • *Marchetti, A., M.S. *Parker, L.P. Moccia, E.O. Lin, A.L. Arrieta, F. Ribalet, M.E.P. Murphy, M.T. Maldonado, and E. V. Armbrust. (2009). A novel ferritin identified in bloom-forming marine pennate diatoms. Nature 457: 467-470. doi:10.1038/nature07539. *These authors contributed equally to this work.
  • Worden, A. et al. (2009). Green evolution and dynamic adaptations revealed by genomes of the marine picoeukaryotes Micromonas. Science 324 (5924): 268 – 272
  • Parker, M.S., T. Mock, and E.V. Armbrust. (2008). Genomic Insights Into Marine Microalgae. Annual Review of Genetics 42:619–45.
  • Bowler, C. et al. (2008). The Phaeodactylum genome reveals the dynamic nature and multi-lineage evolutionary history of diatom genomes. Nature 456:239-244.
  • Erdner, D.L., Dyble, J., Parsons, M.L., Stevens, R.C., Hubbard, K.A., Wrabel, M.L., Moore, S.K., Lefebvre, K.A., Anderson, D.M., Bienfang, P., Bidigare, R.R., Parker, M.S., Moeller, P., Brand, L.E., Trainer, V.L. (2008) Centers for Oceans and Human Health: a unified approach to the challenge of harmful algal blooms. Environmental Health 7(Suppl 2):S2 doi:10.1186/1476-069X-7-S2-S2
  •  Moore, S.K., V.L. Trainer, N.J. Mantua, M.S. Parker, E.A. Laws, L.C. Backer and L.E. Fleming. (2008). Impacts of climate variability and future climate change on harmful algal blooms and human health. Environmental Health 7:(Suppl 2):S4
  • *Kroth, P. G., A. Chiovitti*, A. Gruber*, V. Martin-Jezequel*, T. Mock*, M. S. Parker*, M. S. Stanley*, A. Kaplan, L. Caron, T. Weber, U. Maheswari, E. V. Armbrust, and C. Bowler. A model for carbohydrate metabolism in the diatom Phaeodactylum tricornutum deduced from comparative whole genome analysis. (2008) PLoS ONE 3:e1426. Full Text Link *These authors contributed equally to this work.
  • Montsant, A. A. E. Allen, S. Coesel, A. De Martino, A. Falciatore, M. Heijde, K. Jabbari, U. Maheswari, M. Mangogna, E. Rayko, M. Siaut, A. Vardi, K. E. Apt, J. A. Berges, A. Chiovitti, A. K. Davis, M. Z. Hadi, T. W. Lane, J. C. Lippmeier, D.Martinez, M. S. Parker, G. J. Pazour, M. A. Saito, K. Thamatrakoln, D. S. Rokhsar, E. V. Armbrust, C. Bowler. (2007) Identification and comparative genomic analysis of signaling and regulatory components in the diatom Thalassiosira pseudonana. Journal of Phycology 43:585-604.
  • Parker, M.S. and E.V. Armbrust. (2005). Synergistic effects of light, temperature and nitrogen source on transcription of genes for carbon and nitrogen metabolism in the centric diatom Thalassiosira pseudonana (Bacillariophyceae). Journal of Phycology 41:1142-1153. Full Text Link N.B. This paper was highlighted in the following review: Allen, A.E. (2005). Defining the molecular basis for energy balance in marine diatoms under fluctuating environmental conditions. Journal of Phycology 41: 1073–1076.
  • Armbrust, E. Virginia, John A Berges, Chris Bowler, Beverley R. Green, Diego Martinez, Nicholas H. Putnam, Shiguo Zhou, Andrew E. Allen, Kirk E. Apt, Michael Bechner, Mark A. Brzezinski, Balbir K. Chaal, Anthony Chiovitti, Aubrey K.Davis, Mark S. Demarest, J. Chris Detter, Tijana Glavina, David Goodstein, Masood Z. Hadi, Uffe Hellsten, Mark Hildebrand, Bethany D. Jenkins, Jerzy Jurka, Vladimir V. Kapitonov, N. Kröger, Winnie W.Y. Lau, Todd W. Lane, Frank W. Larimer, J. Casey Lippmeier, Susan Lucas, Mónica Medina, Anton Montsant, Miroslav Obornik, Micaela Schnitzler Parker, B. Palenik, Gregory J. Pazour, Paul M. Richardson, Tatiana A. Rynearson, Mak A. Saito, David C. Schwartz, Kimberlee Thamatrakoln, Klaus Valentin, Assaf Vardi, Frances P. Wilkerson, and D. S. Rokhsar. (2004). The genome of the diatom Thalassiosira pseudonana: Ecology, evolution and metabolism. Science 306: 79-86. Full Text Link
  • Parker, M.S., E.V. Armbrust, J. Piovia-Scott and R G. Keil. (2004). Light regulation of a photorespiratory gene (glycine decarboxylase) in the centric diatom Thalassiosira weissflogii (Bacillariophyceae). Journal of Phycology 40:557-567. Full Text Link
  • Parker, M.S., P.A. Jumars and L. L. LeClair.(2002). Population genetics of two bivalve species (Protothaca staminea and Macoma balthica) in Puget Sound , Washington. Journal of Shellfish Research. 22(3): 681-688.
  • Weir, A.M.; Schnitzler*, M.A.; Tattar, T.A.; Klekowski, E.J. Jr. ; Stern, A.I. (1996). Wound periderm development in red mangrove, Rhizophora mangle (L.). Intl. J. Plant Sci. 157(1): 63-70.
  • Schnitzler*, M.A. (1994). The anatomy of fungal resistance mechanisms in Rhizophora mangle (L.), red mangrove. Undergraduate Honors Thesis. University of Massachusetts, Honors Program.

* maiden name = Schnitzler



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